Duffy said that with the IPO behind them, the company would turn its attention to "execution" in the months ahead.

"You've got the bigger banks, then there's us, then there's the rest," Duffy said. "We're the largest of the challenger banks, and we're the only one with a full-scale SME and full-scale retail business.

"We're in a very strong competitive position," Duffy added. "The other challengers, they talk a lot about customers, but we already have 300m customers."